Is it possible to get chicken pox again,after having it 6 weeks earlier?

Ds2 had chicken pox(quite badly) at the beginning of July,followed by dh and then finally Ds1 2 weeks ago.Dh has just bathed ds2 and has noticed about 15 new spots on his chest,although they're not blistery ones iykwim.Definately do not look like a heat rash,as they're dotted around,rather than in one place.Can it be possible to get it again,so quickly?Thanks